I have the AF1 intake on my 03 Expedition. I've been doing a bit of driving lately in heavy rain. I was thinking about the moisture and just dust/dirt in general.

I know they make these covers for filters when going through deep mud to keep the filter clean. I was just wondering if it would be worth it to put one of those on for daily driving? Either that or, get some of the open cell foam, like they have for lawn mower and motorcycle engine intakes and wrap the AF1 filter with the foam. I'm thinking it wouldn't cut down much on the air flow, but would give another barrier for debris and moisture to have to get through.

Has anyone tried either of these, or are there any informed opinions? (just the informed ones; I have plenty of uninformed opinions of my own already thanks

 

It'd be a shame to wrap your AF1 with open cell foam IMO.. understand the idea behind it but it kinda defeats the purpose of the open filter.. I'd look into an S&B or another enclosed element if you're that concerned about fouling an open filter

 

To the best of my knowledge, a prefilter isn't going to do much with moisture or mud. The purpose is to filter out the larger particles of dust before they make it to the filter. Such as a prefilter will trap dust particles that are .005" or larger, where your regular filter may filter down to 0.001". (not sure if these particle sizes are right, as I just used them for an example) So as long as you keep your prefilter clean there really shouldn't be any problems.

But you say you've been driving in heavy rain lately, so don't worry about dust....

You can always get an oil analysis test done to see the levels of silicon. I know diesel guys who do this before and after changing over to a new aftermarket filter system. OEM may be restrictive, but they will keep the small particles out of your engine...